Is something that can happen to investors when a company, for example, makes a share issue. It is then in cases where the investor is not allowed to participate in the issue that the dilution takes place. Dilution is therefore an effect that occurs when companies print new shares, and the market value of the company is distributed over several shares.
The investor owned shares before the incident and holds an equal number of shares after the issue. When the "dilution" / issue is completed, the investor's shareholding is thus less valuable than before this event. This is due to the new shares that have been added to the company.